File Browser has an Access Rule Bypass via Path Traversal in Copy/Rename Destination Parameter

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS

• CVE-2026-32758: 0.39% estimated exploitation activity in the next 30 days; percentile 33.66 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Description The resourcePatchHandler in http/resource.go validates the destination path against configured access rules before the path is cleaned/normalized. The rules engine (rules/rules.go) uses literal string prefix matching (strings.HasPrefix) or regex matching against the raw path. The actual file operation (fileutils.Copy, patchAction) subsequently calls path.Clean() which resolves .. sequences, producing a different effective path than the one validated. This allows an authenticated user with Create or Rename permissions to bypass administrator-configured deny rules by including .. (dot-dot) path traversal sequences in the destination query parameter of a PATCH request. Steps to Reproduce 1. Verify the rule works normally 2. Exploit the bypass 3. Result The file test.txt is copied to /restricted/copied.txt despite the deny rule for /restricted/. Root Cause Analysis In http/resource.go:209-257: In rules/rules.go:29-35: In fileutils/copy.go:12-17: The rules check sees…

Published by the source

16 Mar 2026, 20:45 UTC

Last modified by the source

20 Mar 2026, 21:15 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-9f3r-2vgw-m8xp

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# Patch Next advisory brief: CVE-2026-32758

Advisory: File Browser has an Access Rule Bypass via Path Traversal in Copy/Rename Destination Parameter
IDs: CVE-2026-32758, GHSA-9f3r-2vgw-m8xp
Record: https://patchnext.com/advisories/cve-2026-32758 (revision 1, source checked 26 Oct 2026, 15:18 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/filebrowser/filebrowser/v2 2.62.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/filebrowser/filebrowser/v2: affected <= 2.61.2; fixed in 2.62.0

## Suggested inspection (read-only)
- Go github.com/filebrowser/filebrowser/v2: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/filebrowser/filebrowser/v2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-9f3r-2vgw-m8xp (GitHub-reviewed advisory GHSA-9f3r-2vgw-m8xp lists affected ranges: Go github.com/filebrowser/filebrowser/v2 >=0 <=2.61.2)

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